Could this be another breakthrough?!?
So if you see Brad (GrnMarvl14)'s link, you'll see that I initially set up a trial of this very idea on Dark Horse.
I originally had whatever page was using the Quote template file itself into the speaker's 'Category:SPEAKER/Quotes' category.
However, this still didn't produce the quotes from that list of pages on the page itself.
Now, after playing with it a bit, I used a tiny bit of DPL to get this done. We can adjust the formatting to whatever we want, but
here's the example. The issue would be similar to the /Appearances issue, that the template has no idea if you're putting in the correct speaker's name in the quote template, it just files the quote regardless of what's there. So running the redirect-fixing bot through the comic pages would fix this for all the comic pages with quotes, but inevitably, we'll have a lot of pages in [[Category:Wolverine/Quotes]] instead of [[Category:James Howlett (Earth-616)/Quotes]] since Wolverine points to a disambig and not the main guy's page.
Still pretty neat though. I'm assuming (with no real basis to do so) that the dpl load on the servers will be minimal since, #1, it'd cached, which means the quotes category pages will only update when they're saved or when the cache gets around to it, and #2, we probably wouldn't be creating every single character we have's quotes category page, but only the ones who either have a quote we know for sure, or show up in the 'wanted categories' special page.

After a little afterthought, we could easily not have this in a category page, but on the same old quotes page, like Hellboy/Quotes. The categories would still exist, out of necessity, but we don't have to have the rest of the page on the category page. So that's an option to this too.